The evolution of automotive paint, from its beginnings, has been linked to the technical possibilities of the time and the requirements that customers have longed for the final product they are going to acquire.
The process of painting used in the first automobiles, was the same one that was used in the painting of carriages. The paints were prepared with resins and vegetable oils and were applied with a brush, the complete process of painting a car was concluded (due to the long drying time) in approximately four weeks.
With the arrival of the metallic body and the beginning of mass production in the first half of the twentieth century, it became technically necessary to achieve faster painting processes, with less drying time and that the paint was not exclusively black, then began the time of diversity in the painted ones of the automobiles.
The first paintings of the era of the series production were nitrocellulose, contributed by the chemical advances of the world-wide wars, which were applied with aerographic guns. Nitrocellulose paints were quick drying, but were not very weather resistant and had the drawback that over time they became cloudy.
By 1933, the most popular technique of painting car bodies was through aerographic guns which used synthetic paints based on alkyd resins, which with the same application technique (spray gun) achieved greater filling power and a glossy finish which did not need polishing, but only allowed the application of a single color.
These paintings were improved over the years to achieve very resistant films that could be baked at 120° C., thus shortening the times demanded drying.
In the 1960s, the era of effect paintings began. Another type of resin, acrylics, began to be used, developing in two different directions: thermoplastic acrylics and thermoplastics of two components. The latter hardened rapidly by baking to achieve a shiny and highly resistant finish. In the same decade of 1960, began to paint automobiles with so-called metallic paints, which included aluminum particles in their composition in order to satisfy the desire of customers to reproduce in the body a metallic effect. But effect paintings had drawbacks; the metal platelets were close to the surface causing them to oxidize and break off over time, creating problems in the duration and repair. Effect paints were one of the first examples in allowing the customization of bodies to customer's liking, such as the incorporation of fire effects, shadows, etc.
In the decades that followed, the labeling of vinyl that subsequently adhered to the vehicle body and the hand-crafted labeling through the “tuning” method for use in automobile personalization appeared in the automotive industry.
Tuning Method
The tuning method, allows to change the appearance of a vehicle after acquiring it, basically means to customize according to the tastes of its owners. The method allows to make changes in the outside as interior of the car achieving its own originality. The main drawback of this method is that it cannot be realized in a series production.
The tuning is made up of three groups:
a. Interior Tuning: The application of several modifications to the various elements and components inside vehicle or also, the changing of these parts with new ones. You can observe the interior of automobiles truly impressive, bright colors, high quality pieces, tapestry for the steering wheel, etc.
b. Motor Tuning: It is perhaps the least extended since in many cases maybe the technical characteristics of the vehicle are changed. Among the modifications that do not vary the characteristics of the engine are: air filters, direct intake and suspension.
c. Tuning Exterior: It is the most widespread group and refers to applying airbrushing on the body. It is a craft technique of decoration for the exterior mainly that can be applied to the personalized car as part of the resources that make the vehicle really unique. To apply the colors to the surface, either flat or three-dimensional, the airbrush is used. The airbrush is the most important tool, which works like a paint gun with compressed air and the paint is expelled by its tip in a conical form. The paint is mixed with pressurized air and is sprayed on exiting so that it can be colored gently, diffusely and faintly. The paint is impregnated on the surface to be decorated depending on the exit angle of the airbrush.
However, labeling through the “tuning” method is considered handcrafted and cannot be applied to a series production, the cost being generally high by depending significantly on the prestige of the “artist” who will make the modifications.
Vinyl Labeling
The process is intended to cover the entire exposed exterior surface of the body to protect the surface and at the same time achieve a new texture, original and even unusual color. Vinyl tuning comes in different aspects included in carbon fiber and can be trimmed in many different ways.
An adhesive vinyl film preserves the original paint of the car and gives it a personalized look. This method is known as plotting because the film copies the entire contour of the vehicle's surface. However, when the adhesive vinyl film has been damaged by the time effect, the film must be replaced and it requires a maximum level of protection to maintain the exterior beauty of the body.
However, like the tuning method, the vinyl does not make a digital impression on a body.
Unlike the above-mentioned techniques, the invention of interest accomplishes the personalization of an automobile through the digital printing of an image provided by the user. In addition, automotive ink (solvent base/water base) as well as eco-solvent printer ink and UV ink, manages to increase the amount of solids in its formulation, thus reducing the proportion of diluents without affecting the characteristics of gloss and hardness that these paints require.
Referring to FIG. 1, it is presented the schematization of the process of application of paint through the areas of application of paint such as:    1A) Application area of the interior body paint through robots,    1B) Exterior painting application zone with 3-axis translation robots and    1C) Application area for exterior body painting through robots, where the W and X robots are used to perform exterior painting applications, and the Y and Z robots are used to perform the custom digital painting process.
FIG. 3 shows the realization of the digital paint application process on the body of a vehicle, FIGS. 2A and 2B, indicate the robots that apply the personalized digital printing on the body. FIG. 2C comprises the body on which the impression will be made and finally FIG. 2D shows the head that will realize the application of the digital impression of the image.
Referring to FIG. 4, it refers to a head of an automated paint robot which is capable of moving and autonomously executing various actions, following the parameters of the image chosen by the client. The articulations of the head allow it to act with degrees freedom by which paint is projected in all the hollows of the body.